U.S. patent number 11,417,900 [Application Number 16/603,198] was granted by the patent office on 2022-08-16 for redox flow battery.
This patent grant is currently assigned to Standard Energy Inc.. The grantee listed for this patent is Standard Energy Inc.. Invention is credited to Bumhee Cho, Damdam Choi, Bugi Kim, Kihyun Kim.
United States Patent |
11,417,900 |
Kim , et al. |
August 16, 2022 |
Redox flow battery
Abstract
The present invention relates to a redox flow battery
comprising: a battery module including a battery cell, an
electrolyte tank, an electrolyte flow path, and an electrolyte
transfer part; and an electrolyte control unit for controlling
electrolyte flow of the battery module, wherein the redox flow
battery comprises one or more battery modules, and is charged or
discharged by an electrolyte independently circulated through every
battery module or every predetermined number of battery modules by
the electrolyte control unit.
Inventors: |
Kim; Bugi (Sejong,
KR), Kim; Kihyun (Daejeon, KR), Cho;
Bumhee (Daejeon, KR), Choi; Damdam (Daejeon,
KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
Standard Energy Inc. |
Daejeon |
N/A |
KR |
|
|
Assignee: |
Standard Energy Inc. (Daejeon,
KR)
|
Family
ID: |
1000006500924 |
Appl.
No.: |
16/603,198 |
Filed: |
January 12, 2018 |
PCT
Filed: |
January 12, 2018 |
PCT No.: |
PCT/KR2018/000578 |
371(c)(1),(2),(4) Date: |
May 14, 2020 |
PCT
Pub. No.: |
WO2018/190496 |
PCT
Pub. Date: |
October 18, 2018 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20200287226 A1 |
Sep 10, 2020 |
|
Foreign Application Priority Data
|
|
|
|
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Apr 10, 2017 [KR] |
|
|
10-2017-0045932 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01M
8/04753 (20130101); H01M 8/04276 (20130101); H01M
8/04186 (20130101); H01M 8/04201 (20130101); H01M
8/188 (20130101); H01M 2250/402 (20130101) |
Current International
Class: |
H01M
8/04276 (20160101); H01M 8/04186 (20160101); H01M
8/04082 (20160101); H01M 8/04746 (20160101); H01M
8/18 (20060101) |
Field of
Search: |
;429/81 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2006-093016 |
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Apr 2006 |
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JP |
|
2009-016218 |
|
Jan 2009 |
|
JP |
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10-2000-0012125 |
|
Feb 2000 |
|
KR |
|
10-2002-0093929 |
|
Dec 2002 |
|
KR |
|
10-2007-0087120 |
|
Aug 2007 |
|
KR |
|
10-2011-0119775 |
|
Nov 2011 |
|
KR |
|
10-1176126 |
|
Aug 2012 |
|
KR |
|
10-2013-0140342 |
|
Dec 2013 |
|
KR |
|
10-1394255 |
|
May 2014 |
|
KR |
|
10-2015-0047529 |
|
May 2015 |
|
KR |
|
10-2017-0005630 |
|
Jan 2017 |
|
KR |
|
10-1803825 |
|
Dec 2017 |
|
KR |
|
10-1803824 |
|
Jan 2018 |
|
KR |
|
WO 2018/190496 |
|
Oct 2018 |
|
WO |
|
Other References
International Search Report dated Apr. 16, 2018 in PCT Application
No. PCT/KR2018/000578. cited by applicant.
|
Primary Examiner: Erwin; James M
Attorney, Agent or Firm: Knobbe, Martens, Olson & Bear,
LLP
Claims
The invention claimed is:
1. A redox flow battery, comprising: a plurality of battery modules
each including a battery cell, an electrolyte tank, an electrolyte
flow path, and an electrolyte transfer part; and an electrolyte
control unit controlling electrolyte flow of the plurality of
battery modules, wherein the plurality of battery modules are
charged and discharged by independently circulating an electrolyte
for each the plurality of battery modules or a predetermined number
of battery modules through the electrolyte control unit.
2. The redox flow battery of claim 1, wherein each of the plurality
of battery modules is configured to include: one or more battery
cells each having a pair of electrodes divided into a positive
electrode and a negative electrode, a membrane interposed between
the electrodes, and a bipolar plate stacked on an outer surface of
each of the electrodes; the electrolyte tank connected to the one
or more battery cells and having an anode electrolyte tank for
causing an anode electrolyte to be circulated and a cathode
electrolyte tank for allowing a cathode electrolyte to be
circulated; the electrolyte flow path connecting the battery cell
and the electrolyte tank; and the electrolyte transfer part
provided in the electrolyte flow path to control flows of the anode
electrolyte and the cathode electrolyte.
3. The redox flow battery of claim 1, wherein the electrolyte
transfer part is provided in the electrolyte flow path connecting
the battery cell and the electrolyte tank or connected to one end
of the electrolyte flow path to be provided in the electrolyte
tank.
4. The redox flow battery of claim 1, wherein the electrolyte
transfer part includes a diaphragm adjusting a pressure inside.
5. The redox flow battery of claim 4, wherein the electrolyte
control unit includes a cam member repeatedly pressurizing the
diaphragm provided in each of the one or more battery modules.
6. The redox flow battery of claim 5, wherein a rotating shaft that
is connected to multiple cam members to cause the multiple cam
members to be eccentrically rotated is provided in a stack
including the plurality of battery modules.
7. The redox flow battery of claim 4, wherein the electrolyte
control unit includes a piezo actuator repeatedly pressurizing the
diaphragm provided in each of the plurality of battery modules.
8. The redox flow battery of claim 4, wherein the diaphragm is made
of a piezo element and controls a pressure inside the electrolyte
transfer part by repeatedly supplying voltage.
9. The redox flow battery of claim 8, wherein the diaphragm is
formed in a concave shape inward of the electrolyte transfer part,
and has a coating layer formed on a surface thereof.
10. The redox flow battery of claim 1, wherein the electrolyte
transfer part includes one or multiple valves inducing flow of the
electrolyte in one direction.
11. The redox flow battery of claim 1, wherein the electrolyte
transfer part includes a piston adjusting a pressure inside.
12. The redox flow battery of claim 1, wherein the electrolyte
transfer part has two or more diaphragms, a cam member, a piezo
actuator, a piezo diaphragm, and a piston.
13. The redox flow battery of claim 1, wherein the electrolyte
transfer part is disposed inside the electrolyte tank.
14. The redox flow battery of claim 13, wherein the electrolyte
transfer part is disposed inside the electrolyte tank in a way such
that a horizontal center axis is positioned to be lower than that
of the electrolyte flow path.
Description
TECHNICAL FIELD
The present invention relates to a redox flow battery that is
charged and discharged as the electrolyte is circulated.
More specifically, the present invention relates to a redox flow
battery, which has at least one battery module including a battery
cell, an electrolyte tank, an electrolyte flow path, and an
electrolyte transfer part in which the electrolyte flows, and
further has an electrolyte control unit controlling the flow of the
electrolyte, whereby each of the battery modules is charged and
discharged by independently circulating an electrolyte.
BACKGROUND ART
Recently, renewable energy, such as solar energy and wind energy,
has been spotlighted as a method of suppressing greenhouse gas
emission, which is a major cause of global warming, and much
research is being carried out for practical use thereof. However,
renewable energy is greatly affected by the site environment and
natural conditions. Moreover, there is a disadvantage in that
renewable energy cannot supply energy evenly continuously because
the output fluctuates severely.
Therefore, in order to produce renewable energy for use in homes or
commercially, a system that stores energy when the output is high
and uses the stored energy when the output is low is being
used.
A large capacity secondary battery is used as such an energy
storage system. For example, the large capacity secondary battery
storage system is introduced in a large-scale photovoltaic and wind
plant. The secondary battery for storing a large amount of power
includes a lead acid battery, a sodium sulfide (NaS) battery, a
redox flow battery (RFB), and the like.
These redox flow batteries have features of operating at room
temperature and enabling independent design of capacity and output,
and thus much research thereon has been conducted as large capacity
secondary batteries.
The redox flow battery is provided so that a membrane, an
electrode, and a bipolar plate are arranged in series to form a
stack, and functions as a secondary battery capable of charging and
discharging electrical energy. The redox flow battery is provided
so that the anode and cathode electrolytes supplied from the anode
and cathode electrolyte storage tanks on both sides of the bipolar
plate are circulated to perform ion exchanges, and in this process,
the movements of the electrons occur to perform charging and
discharging. Such a redox flow battery is known to be most suitable
for an energy storage system (ESS) because the redox flow battery
has a longer lifespan compared with the existing secondary battery
and can be manufactured in all medium and large systems of kW to MW
class.
However, the redox flow battery is configured so that the tanks for
storing the anode and cathode electrolytes are separately arranged
at a predetermined spacing (for example, the electrolyte tanks are
arranged at a predetermined spacing in both sides or the bottom of
the stack). Due to the electrolyte circulation pipe connecting the
tank and the electrolyte tank, there is a disadvantage in that the
overall volume of the system is relatively large compared to other
power storage devices such as lead acid batteries, lithium ion
batteries, and lithium-sulfur batteries having a similar power
storage capacity.
In addition, since a plurality of electrolyte circulation tubes are
connected to the stack, the pump and the electrolyte tank must be
provided, and a pump capacity of a certain level or more is
required to supply electrolyte to each stack uniformly. There are
problems that as the length of the electrolyte circulation tube is
increased, the required capacity of the pump is increased so that
the size of the pump and the manufacturing cost of the battery are
increased, and as the power consumption is increased due to the
increase in the pump capacity, the overall battery efficiency is
reduced.
In addition, the general battery should have fast response to the
charging and discharging operation. However, when the redox flow
battery is operated for charging and discharging in a stopped
state, it takes time for the electrolyte to circulate into the
stack using the pump, whereby there are problems that the response
is delayed as much as the required time and the cost increases
because a large amount of chemical-resistant piping is required to
connect the cell, the stack, and the pump.
A typical redox flow battery is provided so that the electrolyte is
supplied to each battery cell through a manifold. However, the
electrolyte filled in the manifold serves as an electric path
connecting each cell, which may be a path of electron movement.
Through this path, a shunt current is generated, and a part of the
energy is lost due to the shunt current during charging and
discharging, which results in the main cause of reduced efficiency,
component damage, and uneven cell performance. The method of
increasing the manifold length and narrowing the cross-sectional
area has been mainly adopted to reduce the shunt current in the
related art. However, since the method increases the flow
resistance of the fluid and the pumping loss, there is a need for a
method to overcome the same.
RELATED DOCUMENTS
Patent Documents
Korean Patent Publication No. 10-2011-0119775 (Nov. 2, 2011)
Korean Patent No. 10-1176126 (Oct. 26, 2011)
DISCLOSURE
Technical Problem
The present invention has been made keeping in mind the above
problems occurring in the related art, and an objective of the
present invention is to provide a redox flow battery that has one
or more battery modules including a battery cell, an electrolyte
tank, and an electrolyte flow path through which the electrolyte
flows; and an electrolyte control unit controlling the flow of the
electrolyte, thereby reducing the reaction time, minimizing the
occurrence of shunt current, and improving the efficiency.
In addition, another objective of the present invention is to
provide a redox flow battery that includes a diaphragm controlling
pressure inside an electrolyte transfer part, the diaphragm being
repeatedly pressurized by the electrolyte control unit to control
the pressure inside the electrolyte transfer part, whereby each of
the battery modules is charged and discharged by individually
circulating the electrolyte.
Technical Solution
In order to achieve the above objectives, a redox flow battery
according to the present invention is configured to include one or
more battery modules each including a battery cell, an electrolyte
tank, an electrolyte flow path, and an electrolyte transfer part;
and an electrolyte control unit controlling electrolyte flow of the
battery module, wherein each of the battery modules is charged and
discharged by independently circulating an electrolyte for each of
the battery modules or a predetermined number of battery modules
through the electrolyte control unit.
Advantageous Effects
The present invention has an advantage that a redox flow battery
has one or more battery modules including a battery cell, an
electrolyte tank, and an electrolyte flow path through which the
electrolyte flows; and an electrolyte control unit controlling the
flow of the electrolyte, whereby each of the battery modules is
charged and discharged by independently circulating an
electrolyte.
In addition, according to the present invention, a redox flow
battery includes a diaphragm controlling pressure inside an
electrolyte transfer part, the diaphragm being repeatedly
pressurized through the electrolyte control unit to control the
pressure inside the electrolyte transfer part, whereby a closed
structure composed of battery cell, electrolyte tank, electrolyte
flow path, and electrolyte transfer part is provided, thereby
reducing the response time, minimizing the occurrence of shunt
current, and improving the efficiency, and each of the battery
modules is charged and discharged by individually circulating the
electrolyte.
DESCRIPTION OF DRAWINGS
FIG. 1 is a view illustrating an example in which multiple battery
modules are provided in a redox flow battery according to the
present invention.
FIG. 2 is a view illustrating an internal structure of the battery
module in a redox flow battery according to the present
invention.
FIG. 3 is a view illustrating an example in which an electrolyte
transfer part is provided in an electrolyte tank in a redox flow
battery according to the present invention.
FIG. 4 is a view illustrating an example of an electrolyte transfer
part and an electrolyte control unit that independently circulate
the electrolyte of each of one or more battery modules in a redox
flow battery according to the present invention.
FIG. 5 is a view illustrating another example of an electrolyte
transfer part and an electrolyte control unit, that independently
circulate the electrolyte of each of one or more battery modules in
a redox flow battery according to the present invention.
FIG. 6 is a view illustrating another example of an electrolyte
transfer part and an electrolyte control unit that independently
circulate the electrolyte of each of one or more battery modules in
the redox flow battery according to the present invention.
FIG. 7 is a view illustrating an example of a valve provided in an
electrolyte transfer part in a redox flow battery according to the
present invention.
FIG. 8 is a view illustrating another example of a valve provided
in an electrolyte transfer part in a redox flow battery according
to the present invention.
FIG. 9 is a view illustrating another example of a valve provided
in an electrolyte transfer part in a redox flow battery according
to the present invention.
FIG. 10 is a view illustrating an example in which the electrolyte
is moved through the electrolyte tank, the electrolyte transfer
part, and the electrolyte control unit independently configured in
multiple battery cells in a redox flow battery according to the
present invention.
FIG. 11 is a view illustrating an example in which a module
connection unit is provided in a redox flow battery according to
the present invention.
BEST MODE
Advantages and features of the embodiments of the present
invention, and methods of achieving them will be apparent with
reference to the embodiments described below in detail with the
accompanying drawings. However, the present invention is not
limited to the embodiments disclosed below, but can be implemented
in various different forms. The embodiments are to make the
disclosure of the present invention complete and are provided to
fully inform the scope of the invention to those skilled in the art
to which the present invention pertains. The invention is defined
only by the scope of the claims. Like reference numerals refer to
like elements throughout.
Upon describing the embodiments of the present invention, if it is
determined that a detailed description of a known function or
configuration may unnecessarily obscure the gist of the present
invention, the detailed description thereof will be omitted. Terms
and words used in the present specification and claims are terms
defined in consideration of functions in the embodiments of the
present invention, and should not be construed as being limited to
ordinary or dictionary meanings. It should be interpreted as
meaning and having a concept corresponding to the technical idea of
the present invention based on the principle that the concept of
the term can be properly defined in order to explain in the best
way.
Therefore, since the embodiments described in the present
specification and the configuration shown in the drawings are only
the most preferred embodiments of the present invention and do not
represent all of the technical idea of the present invention, it
should be understood that there may be various equivalents and
variations capable of being substituted therefor at the time of the
present application.
Before describing the present invention with reference to the
drawings, it should be appreciated that matters that are not
necessary to reveal the gist of the present invention, that is,
well-known configurations that could be obviously added by those
skilled in the art will not be shown or described in detail.
A redox flow battery according to the present invention is provided
with at least one battery module including a battery cell, an
electrolyte tank, an electrolyte flow path, and an electrolyte
transfer part in which the electrolyte flows, and further provided
with an electrolyte control unit for controlling the flow of the
electrolyte, whereby each of the battery modules is charged and
discharged by independently circulating an electrolyte.
The redox flow battery according to the present invention is
devised to overcome a problem that the length of the electrolyte
circulation tube is increased and thus the volume of the battery
itself is increased, which is a disadvantage of the redox flow
battery, a physical problem that a high performance pump is
required or the number of pumps is increased, a problem that the
size of the pump and the manufacturing cost of the battery are
increased due to the transfer of electrolyte, and a problem that
the responsiveness is reduced and pumping loss occurs, the redox
flow battery having one or more battery modules 10 consisting of a
battery cell 110, an electrolyte tank 120, an electrolyte flow path
130, and an electrolyte transfer part 140 provided on a stack 10,
and having an electrolyte control unit 200 that controls such that
the electrolyte transfer part 140 is operated to cause the
electrolyte to be circulated, whereby each of the multiple battery
modules 100 is charged and discharged by independently circulating
the electrolyte. Thus, the present invention can significantly
reduce the moving distance of the electrolyte, and can efficiently
solve problems such as delayed response, pumping loss, and the
like.
First, a battery cell 110 provided in a battery module 100 herein
means a minimum unit in which charging and discharging are
performed through the electrolyte.
In addition, a stack 10 herein means that one or more battery cells
110 are provided, in which multiple battery cells 110 are stacked
or configured.
Hereinafter, with reference to the accompanying drawings, the redox
flow battery according to the present invention will be described
in detail.
FIG. 1 is a view illustrating an example in which multiple battery
modules are provided in a redox flow battery according to the
present invention, and FIG. 2 is a view illustrating an internal
structure of the battery module in a redox flow battery according
to the present invention.
FIGS. 1 and 2 are schematic structural diagrams illustrating the
structure of a redox flow battery according to the present
invention. Referring to FIGS. 1 and 2, a stack 10 is configured to
include one or more battery modules 10 and an electrolyte control
unit 200, in which each of the battery modules 100 includes a
battery cell 110, an electrolyte tank 120, an electrolyte flow path
130, and an electrolyte transfer part 140.
Referring to FIGS. 1 and 2, the battery cell 110 is configured to
include a membrane 112 interposed between a positive electrode 111a
and a negative electrode 111b composing a pair of electrodes 111,
and a bipolar plate 113 spaced apart from the outside of each of
the electrode 111, in which the battery cell 110 has a flow path
formed therein so that the anode electrolyte and the cathode
electrolyte is alternatively supplied.
That is, when the electrolyte is to be transported by the operation
of the electrolyte control unit 200 which will be described later,
the electrolyte is transferred from the electrolyte tank 120 to the
battery cell 110 through the electrolyte flow path 130 to be
circulated.
Through this circulation process, it is possible to perform
charging and discharging.
Meanwhile, the battery cell 110 herein is described and illustrated
on the basis of a typical redox flow battery, and configurations of
the electrode 111, the membrane 112, or the bipolar plate 113 may
be omitted, depending on the design conditions.
The electrolyte tank 120 is provided inside the battery module 100,
connected to the battery cell 110 through the electrolyte flow path
130 to be described later, and configured to include an anode
electrolyte tank 121 in which the anode electrolyte is circulated
and a cathode electrolyte tank 122 in which the cathode electrolyte
is circulated.
Depending on the design conditions, the electrolyte tank 120 is
provided in each of the battery module 100 or connected to multiple
battery modules 100 through the electrolyte flow path 130 to be
described later so that the multiple battery modules 100 may be
connected to share the electrolyte tank 120.
For example, two or more battery modules 100 are connected to one
electrolyte tank 120 through the respective electrolyte flow paths
130, so that the electrolyte of the electrolyte tank 120 may be
transferred to each of the two or more battery modules 100 through
the respective electrolyte flow paths 130 and then circulated.
The electrolyte flow path 130 connects the battery cell 110 to the
electrolyte tank 120 to provide a space in which the electrolyte
flows, and as shown in FIGS. 1 and 2, a pair of flow paths are
formed so that the anode electrolyte and the cathode electrolyte
are supplied and discharged between the anode electrolyte tank 121
and the battery cell 110 and between the cathode electrolyte tank
122 and the battery cell 110, respectively.
Thus, the anode electrolyte of the anode electrolyte tank 121 is
supplied to the battery cell 110 along one of the pair of flow
paths, the anode electrolyte passing through the battery cell 110
is discharged along other flow path and then introduced into the
anode electrolyte tank 121, thereby enabling the anode electrolyte
to be circulated.
In addition, the cathode electrolyte of the cathode electrolyte
tank 122 is supplied to the battery cell 110 along one of the pair
of flow paths, and the cathode electrolyte passing through the
battery cell 110 is discharged along the other flow path and then
introduced into the cathode electrolyte tank 122, thereby enabling
the cathode electrolyte to be circulated.
Thus, the battery cell 110 including the positive electrode 111a,
the negative electrode 111b, the membrane 112, and the bipolar
plate 113 is provided such that the anode electrolyte and the
cathode electrolyte circulated from the anode electrolyte tank 121
and the cathode electrolyte tank 122 electrochemically react with
each other in the battery cell 110, whereby charging or discharging
is performed.
Referring to FIGS. 1 and 2, the electrolyte transfer part 140 is
provided in the electrolyte transfer part 140 and serves to control
the flow of the anode electrolyte and the cathode electrolyte
through the electrolyte control unit 200 which will be described
below. The electrolyte transfer part 140 may be made in the form of
a housing having a space therein, and configured to include a
diaphragm 141.
The diaphragm 141 is provided inside the electrolyte transfer part
140 and stretched by the electrolyte control unit 200 which will be
described, thereby changing the pressure in the electrolyte
transfer part 140.
The diaphragm 141 is provided inside the electrolyte transfer part
140 and stretched via the operation of the electrolyte control unit
200 which is provided in the outer side thereof. The diaphragm 141
is preferably made of a material which is excellent in
watertightness and elasticity. When the electrolyte control unit
200 to be described below is operated, the diaphragm 141 is
stretched inward or outward of the electrolyte transfer part 140,
thereby changing the pressure inside the electrolyte transfer part
140. The electrolyte may flow through the electrolyte flow path 130
by such pressure change in the electrolyte transfer part 140.
Herein, the diaphragm 141 does not limit types of materials. For
example, the diaphragm 141 may be made of a material such as
rubber, and materials that are excellent in watertightness and
elasticity, for example, fluororubber (trade name Viton) such as
tetrafluoroethylene and perfluoromethyl vinyl ester, ethylene
propylene terpolymer (EPDM), and the like.
In addition, the shape of the diaphragm capable of being used in
the present invention is not limited when a shape capable of
transmitting the pressure described herein, such as a flat shape, a
specific concave-convex shape, or a bellows shape. Alternatively,
in addition to the valve, it is possible to apply a structure that
changes the pressure inside the electrolyte transfer part by
reciprocating motion while being sealed, such as a piston (not
shown in the drawing)
Meanwhile, although the redox flow battery according to the present
invention is provided so that the electrolyte transfer part 140 is
provided in the electrolyte flow path 130 connecting the battery
cell 110 with the electrolyte tank 120, as shown in FIGS. 1 to 2,
the electrolyte transfer part 140 may be located inside the
electrolyte tank 120, as shown in FIG. 3.
Thus, when a positive pressure is transferred to the electrolyte
transfer part 140 through the operation of the electrolyte control
unit 200 to be described later, the electrolyte in the electrolyte
transfer part 140 is transmitted to a battery cell 110 through the
electrolyte flow path 130, and the level of the electrolyte in the
electrolyte transfer part 140 is naturally lowered, so that the
difference between the electrolyte level inside the electrolyte
transfer part 140 and the electrolyte level outside the external
electrolyte, that is, inside the electrolyte tank 120 is generated.
Herein, when the level of the electrolyte is lowered and the supply
of the positive pressure is stopped, the electrolyte inside the
electrolyte tank 120 inflows into the electrolyte transfer part 140
through the height difference of the electrolyte, whereby it is
possible to minimize the supply of the negative pressure required
for the electrolyte inflow, thereby obtaining a large effect even
with less energy. It is possible that the electrolyte inflows into
the electrolyte transfer part 140 without supplying negative
pressure, thereby improving the battery efficiency.
Herein, the circulation of the anode electrolyte or the cathode
electrolyte may be made by the operations of the electrolyte
transfer part 140 and the electrolyte control unit 200 that
controls the flow of the electrolyte.
The electrolyte control unit 200 serves to control the flow of
electrolyte of each of one or more battery modules 100. Preferably,
the electrolyte control unit 200 performs a function of changing
the pressure in the electrolyte transfer part 140 by stretching the
diaphragm 141 of the electrolyte transfer part 140, in which the
pressure in the electrolyte transfer part 140 is changed through
the operation of the electrolyte control unit 200 to allow the
electrolyte to flow.
Here, the transferring of the electrolyte from the electrolyte
transfer part 140 along the electrolyte transfer path 130 may be
due to a principle according to the pressure difference in the
electrolyte transfer part 140.
That is, when the diaphragm 141 is stretched inward of the
electrolyte transfer part 140 so that the pressure in the
electrolyte transfer part 140 is lowered, the negative pressure
acts, whereby the electrolyte inflows into the electrolyte transfer
part 140, so as to maintain the pressure balance in the electrolyte
transfer part 140. On the contrary, when the diaphragm 141 is
stretched outward of the electrolyte transfer part 140 so that the
pressure in the electrolyte transfer part 140 increases, the
positive pressure acts, whereby the electrolyte in the electrolyte
transfer part 140 naturally inflows into the battery cell 110 along
the electrolyte flow path 130.
Through the repetition of this process, the electrolyte inflows
into the battery cell 110 and then circulated.
Hereinafter, with reference to FIGS. 4 to 6, the electrolyte
control unit 200 will be described in detail.
FIG. 4 is a view illustrating an example of an electrolyte transfer
part and an electrolyte control unit that independently circulate
the electrolyte of each of one or more battery modules in a redox
flow battery according to the present invention.
Referring to FIG. 4, the electrolyte control unit 200 is to
repeatedly press the diaphragm 141 provided in each of the one or
more battery modules 100 to cause the diaphragm 141 to be
stretched, and is configured to include a cam member 211 and a
rotation shaft 212.
The cam member 211 is provided outside the electrolyte transfer
part 140 which is provided on each of the one or more battery
modules 100 provided in the stack 10, and performs a function of
repeatedly pressurizing the diaphragm 141 provided in the
electrolyte transfer part 140 during eccentric rotation with
respect to the axis of rotation, whereby the diaphragm 141 is
stretched inward of the electrolyte transfer part 140 or stretched
outward of the electrolyte transfer part 140.
As shown in FIG. 4, the cam member 211 is preferably provided in
each of one or more battery modules 100, and multiple cam members
211 share a rotating shaft 212 to be described later, and thus are
connected to the rotating shaft 212.
The rotating shaft 212 is connected to the multiple cam members 211
to cause the multiple cam members 211 to be eccentrically rotated,
and is preferably provided in the stack 10 as shown in FIG. 4,
thereby allowing the diaphragm 141 of the electrolyte transfer part
140 provided in each of the one or more battery modules 100
provided in the stack 10 to be pressurized and stretched.
That is, when the rotating shaft 212 is rotated, the multiple cam
members 211 connected to the rotating shaft 212 are eccentrically
rotated so that the diaphragm of the electrolyte transfer part 140
provided in each battery module 100 is pressurized. As the
stretching of the diaphragm 141 is repeatedly performed, each of
the battery modules 100 may be independently charged and discharged
by circulation of the electrolyte due to the pressure change in the
electrolyte transfer part 140. Herein, the cam member and the valve
may be mechanically coupled to each other, such as by a linkage or
direct coupling, or the aforementioned electrolyte transfer part
may be driven without being coupled.
FIG. 5 is a view illustrating another example of an electrolyte
transfer part and an electrolyte control unit, which independently
circulate the electrolyte of each of one or more battery modules in
a redox flow battery according to the present invention.
Referring to FIG. 5, another example of an electrolyte control unit
200 will be described. The electrolyte control unit 200 may be
configured with a piezo actuator 221 that repeatedly pressurizes
the diaphragm 141 provided in each of the one or more battery
modules 100.
Here, the piezo actuator 221 is a positioning element that applies
the piezoelectric effect, and has constant operating frequency
(repetitive operation) and excellent accuracy, whereby there is an
advantage that accurate positioning may be performed from a few
nanometers to hundreds of microns.
In detail, the piezo actuator 221 is a type of actuator using the
principle of piezoelectric effect, in which when a voltage is
applied, deformation is generated in proportion to voltage.
Multiple piezo actuators 221 are provided in such a manner as to be
coupled to the support shaft 222 provided in the stack 10, as shown
in FIG. 5.
Since the multiple piezo actuators 221 are provided in such a
manner as to be coupled to the support shaft 222, it is possible to
maintain the same height as the diaphragm 141 of each of the one or
more battery modules 100 provided in the stack 10 and thus ensure
that the flow of the electrolyte is fine and accurate through
control of the diaphragm 141.
More specifically, the redox flow battery according to the present
invention utilizes the piezo actuator 221 to stretch the diaphragm
141 of the electrolyte transfer part 140 which is provided in each
of the one or more battery module 100 in the stack 10, whereby the
diaphragm 141 provided in the electrolyte transfer part 140 is
repeatedly pressurized by utilizing the principle that the actuator
has a variable length through the supply of voltage to the piezo
actuator 221. Accordingly, as the diaphragm 141 is stretched, the
electrolyte may be transported and thus eventually circulated.
In detail, as shown in FIG. 5, when the voltage is supplied to the
piezo actuator 221, the length is repeatedly varied, and the
diaphragm 141 of the electrolyte transfer part 140 is repeatedly
pressurized according to the varied length, whereby a process of
stretching the diaphragm 141 inward and outward of the electrolyte
transfer part 140 is repeated so that the pressure inside the
electrolyte transfer part 140 is changed to allow the electrolyte
to be transferred.
Accordingly, the electrolyte is circulated by varying the pressure
in the electrolyte transfer part 140 provided in each of one or
more battery modules 100 provided in the stack 10, so that each of
the battery modules 100 may be independently charged and
discharged.
FIG. 6 is a view illustrating another example of an electrolyte
transfer part and an electrolyte control unit that independently
circulates the electrolyte of each of one or more battery modules
in the redox flow battery according to the present invention.
Another example of an electrolyte transfer part 140 and an
electrolyte control unit 200 will be described with reference to
FIG. 6. The electrolyte transfer part 140 is provided with a
diaphragm 141, and the diaphragm 141 may be made of a piezo
element.
In addition, although the electrolyte control unit 200 is not shown
in the drawings, it may be made of a separate power supply means
capable of supplying a voltage to the diaphragm 141 made of a piezo
element.
Here, the piezo element is operated on the basis of the same
principle as the piezo actuator 221 described above, in which the
deformation is generated in proportion to the voltage supplied.
That is, by supplying a voltage to the diaphragm 141 made of a
piezo element, the diaphragm 141 is stretched inward of the
electrolyte transfer part 140, as shown in FIG. 6, so that the
pressure in the electrolyte transfer part 140 is changed and thus
the electrolyte is transferred according to the pressure
change.
Herein, the diaphragm 141 made of a piezo element is preferably
made of a concave shape inward of the electrolyte transfer part
140, as shown in FIG. 6.
This, when the diaphragm 141 made of a piezo element is provided in
a straight form or a convex shape outward of the electrolyte
transfer part 140, the influence on the pressure change and the
electrolyte in the electrolyte transfer part 140 is insufficient
because the diaphragm 141 is stretched outward of the electrolyte
transfer part 140 by the supply of voltage. Thus, the diaphragm 141
has the concave shape inward to prevent the problem. As shown in
FIG. 6, the diaphragm 141 is formed in a concave shape inward of
the electrolyte transfer part 140, so that the diaphragm 141 is
always stretched inward of the electrolyte transfer part 140, that
is, in one direction, by the supply of voltage, whereby the
pressure change and the electrolyte transfer in the electrolyte
transfer part 140 may be performed more efficiently and
accurately.
Depending on the design conditions, a coating layer 141a may be
formed on the surface of the diaphragm 141 made of the piezo
element.
The coating layer 141a is coated on the surface of the diaphragm
141 to protect the diaphragm 141 and ensure excellent acid
resistance, in order to complement the acid-vulnerable properties
of the piezoelectric element.
Accordingly, it is possible to prevent a problem that the redox
flow battery does not function properly as a part of the diaphragm
141 is failed or damaged.
Herein, the coating layer 141a may be formed with an acid resistant
coating, and may be made of one or more acid resistant coatings
selected from the group consisting of silicon compounds, boron
compounds, and aluminum compounds. Preferably, the redox flow
battery according to the present invention is provided so that the
diaphragm 141 made of a piezo element is stretched, in which the
coating layer 141a may be formed of any coating agent, if the
coating agent is excellent in acid resistance while preventing the
coating layer 141a from being separated or lost while the valve 141
is stretched.
In addition, in the redox flow battery according to the present
invention, methods of using a cam, a diaphragm, a piston, a piezo,
and a piezo diaphragm for driving the electrolyte transfer part
have been described, it is also possible to apply one or more of
these means in combination. For example, two methods may be
combined by using the piezo diaphragm while using the cam
structure. Accordingly, it is possible to select a suitable method
of two methods according to the situation, by which the electrolyte
transfer part is driven only by the piezo diaphragm when the
required flow rate of electrolyte is low, and the electrolyte
transfer part is driven only by the cam or driven by the cam and
piezo diaphragm together when the required flow rate of electrolyte
is increased.
Hereinafter, an example in which a configuration of a valve 142 for
adjusting a direction in which an electrolyte flows in a redox flow
battery according to the present invention is added will be
described with reference to FIGS. 7 to 9.
First, it is noted that the same content as described in FIGS. 1 to
6 is not mentioned.
Referring to an example in which the configuration of the valve 142
is added in the redox flow battery according to the present
invention, the battery module 100 is added, the battery module 100
is configured to include a battery cell 110, an electrolyte tank
120, and electrolyte flow path 130, and an electrolyte transfer
part 140, in which the electrolyte transfer part 140 has a valve
142 which induces the flow of the electrolyte in one direction.
FIG. 7 is a view illustrating an example of a valve provided in the
electrolyte transfer part in a redox flow battery according to the
present invention.
Referring to FIG. 7, an example of the valve 142 will be described.
The valves are provided on both sides of the electrolyte transfer
part 140, and one pair of valves is included in the electrolyte
flow path 130.
The valve 142 is preferably configured with a non-return valve, and
is operated so that the flow of the electrolyte is guided in one
direction.
Herein, as shown in FIG. 7, the valve 142 may be composed of a pair
of check valves. When the pressure in the space inside the
electrolyte transfer part 140, that is, the space pressure between
the pair of check valves is operated (negative pressure) to be
lowered by the operation of the electrolyte control unit 200, the
space pressure between the pair of check valves is naturally
lowered. Therefore, in order to maintain pressure equilibrium, the
electrolyte flows into the electrolyte transfer part 140 through
one check valve provided on the side of the electrolyte flow path
130 by which the electrolyte is flowed into the electrolyte
transfer part 140, and the other check valve provided on the side
of the electrolyte flow path 130 by which the electrolyte is
discharged from the electrolyte transfer part 140 is closed,
thereby preventing the reverse flow of the electrolyte.
In addition, when the electrolyte control unit 200 is operated
(positive pressure) so that the pressure of the space inside the
electrolyte transfer part 140, that is, space between the pair of
check valves is increased, the electrolyte in the electrolyte
transfer part 140 inflows into the battery cell through the other
check valve, and one check valve 142 is closed.
By repeating this process, the electrolyte is transferred from the
electrolyte tank 120 to the battery cell 110, and transferred from
the battery cell 110 to the electrolyte tank 120 back, whereby the
electrolyte is circulated in one direction.
Herein, the configuration of the valve 142 is made of a valve in
the form of a disk, as shown in FIG. 8, in addition to the check
valve shown in FIG. 7, or made of a valve operated by pressure as
shown in FIG. 9.
The valve in the form of a disk or the valve operated by pressure
is operated in the same way as the check valve. The flow resistance
is higher in the reverse direction than in the forward direction in
the flow of the electrolyte, so that the electrolyte generally
flows in the forward direction, thereby allowing the circulation of
the electrolyte to proceed in one direction.
According to the design conditions, various embodiments of the
valve are described referring to FIGS. 7 to 9, the present
invention is not limited thereto. As long as the valve is provided
in the electrolyte flow path 130 or the electrolyte transfer part
140 to cause the electrolyte to flow in one direction, the valve
may be of any configuration.
In addition, FIGS. 7 to 9 illustrate a form in which a pair of
valves 142 is provided. In general, the inside of the battery cell
110 has a high fluid flow resistance, and only one valve 142 may be
provided in the electrolyte flow path 130, according to
necessity.
As such, when the electrolyte flows through the electrolyte
transfer part 140 and the electrolyte control unit 200, the flow of
the electrolyte may be induced in one direction using the valve 142
to prevent the reverse flow, whereby the redox flow battery can be
efficiently charged and discharged according to the circulation of
the electrolyte.
Depending on the design conditions, when there are problems that
the diaphragm 141 provided in the electrolyte transfer part 140 is
damaged or the pressure is not easily changed during controlling
the pressure in the electrolyte transfer part 140 to control the
flow of the electrolyte, a pressure gauge (not shown) may be
further provided to measure the same.
Accordingly, when the loss of pressure occurs through the pressure
gauge, the detection and notification thereof is performed so that
the administrator may recognize the same, to make it possible to
supplement the lost pressure or check and repair various
configurations.
According to this configuration, the redox flow battery according
to the present invention has one or more battery modules including
the battery cell 110, the electrolyte tank 120, the electrolyte
flow path 130, and the electrolyte transfer part 140 though which
electrolyte flows, and further has an electrolyte control unit 200
that controls the flow of the electrolyte, whereby each of the
battery modules 100 is charged and discharged by independently
circulating the electrolyte.
In addition, the diaphragm is provided to control the pressure
inside the electrolyte transfer part, the diaphragm being
repeatedly pressurized through the electrolyte control unit so that
the pressure inside the electrolyte transfer part may be
controlled, whereby the electrolyte is circulated through the
sealed structure composed of the battery cell, the electrolyte
tank, the electrolyte flow path, and the electrolyte transfer part,
thereby reducing the reaction time, minimizing the generation of
shunt current, and improving the efficiency.
In addition, since there is no need to drive a motor or pump to
circulate the electrolyte for each battery module 100, the energy
efficiency may be increased, the circulation distance of the
electrolyte is reduced to increase the responsiveness of the
battery and minimize the use of acid-resistant piping.
Meanwhile, the redox flow battery according to the present
invention has been described as an example of an independent
configuration composed of the battery cell 110, the electrolyte
tank 120, the electrolyte flow path 130, and the electrolyte
transfer part 140, in which the electrolyte tank 120 and the
electrolyte transfer part 140 may be provided to be used in common
and multiple battery cells 110 may be included.
This will be described in detail with reference to FIG. 10.
FIG. 10 is a view illustrating an example in which the electrolyte
is moved through the electrolyte tank, the electrolyte transfer
part, and the electrolyte control unit independently configured in
multiple battery cells in the redox flow battery according to the
present invention.
As shown in FIG. 10, the battery module is configured so that
multiple battery cells 110 are provided, the multiple battery cells
110 are connected to the anode electrolyte tank 121 and the cathode
electrolyte tank 122 through the electrolyte flow path 130, and the
electrolyte transfer part 140 controlling the flow of fluid is
provided in each of the electrolyte flow path 130 connected to the
anode electrolyte tank 121 and the electrolyte flow path 130
connected to the cathode electrolyte tank 122.
Herein, when the electrolyte control unit 200 is operated, the
diaphragm 141 of the electrolyte transfer part 140 is stretched, in
which due to the pressure change in the electrolyte transfer part
140, the anode electrolyte is circulated through the anode
electrolyte tank 121, the electrolyte flow path 130, and the
multiple battery cells 110, and the cathode electrolyte is
circulated through the cathode electrolyte tank 122, the
electrolyte flow path 130, and the multiple battery cells 110, so
that each of the multiple battery cells 110 may be independently
charged or discharged, or multiple battery cells are coupled in a
stack shape while sharing the configurations except the battery
cell 110.
According to the design conditions, the redox flow battery
according to the present invention may further include a module
connection unit 300 that electrically connects between multiple
battery modules 100 provided in the stack 10.
Referring to FIG. 11, the module connection unit 300 electrically
connects the multiple battery modules 100 to perform a function of
allowing the battery modules 100 to electrically communicate with
each other.
Herein, the module connection unit 300 is preferably made of a
conductive material, and is used with wires made of aluminum or
copper depending on the design conditions.
Further, a wire made of gold or plated with gold may be used to
prevent corrosion of the wires, and any conductor may be used as
long as it is electrically conductive.
In some cases, the battery modules 100 may be configured in such a
manner as to be driven independently without an electrical
connection between the battery modules 100, and a desired output
may be configured through a serial or parallel connection.
According to this configuration, the redox flow battery according
to the present invention can circulate the electrolyte
independently to minimize the generation of shunt current without
any interference or exchanges of electrolyte between multiple
battery modules 100. Alternatively, several battery modules 100
share the electrolyte tank 120 to circulate the electrolyte, the
battery module having a battery cell 110, an electrolyte transfer
part 14, and an electrolyte flow path 130. Several battery modules
share one anode electrolyte tank and one cathode electrolyte tank
to be driven, thereby minimizing the generation of shunt
current.
In the above description, various embodiments of the present
invention have been described and described, but the present
invention is not necessarily limited thereto, and a person having
ordinary skill in the art to which the present invention pertains
will understand that various substitutions, modifications, and
changes can be made therein without departing from the technical
spirit of the present invention.
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